Hadi and Mehdi Zandi (defendants) were brothers living in the United States who had a third brother, Morteza, living in Pakistan. Hadi and Mehdi had telephone conversations with Morteza in which they discussed paying Morteza $3,000 for Morteza to mail them a box of “presents” that could then be sold in the United States. Hadi and Mehdi sent the money to Morteza, and Morteza send a package with a false shipping address to a post office box provided by Mehdi. After learning the package had been delivered to the United States, Mehdi and Hadi obtained the airway bill receipt and the carrier’s certificate. Mehdi paid the storage fee required to pick up the package, and requested the package at the warehouse. Upon learning that a customs inspector was present at the warehouse, however, Mehdi abruptly left. The warehouse staff became suspicious and alerted the customs official. The official inspected the package and discovered that it contained opium. The next day Hadi and Mehdi returned and again requested the package with the required documentation. After Hadi was handed the package, a custom official asked him to open it for inspection and Hadi complied, revealing the opium. Hadi and Mehdi were both arrested, charged, and convicted of possession of opium with the intent to distribute. Hadi and Mehdi appealed on the grounds that the government (plaintiff) failed to establish that they actually possessed the opium or had knowledge that opium was in the package.